computer networks connect computers together for the purpose of sharing personal communiction, hardware, software resources and info
set of independent computer systems interconnected by telecommunication links for the purpose of sharing info and resources
nodes/hosts - individual computers on a network wich can range from the size of smartphones, tiny computers to massive supercomputers
used to build a network very widely in physical characteristics, error rate, and transmission speed
moderm - a device that restructures binary signals into analog representations by modulating or altering a standard analog signal called a "carrier wave" so it encodes binary info
conencts hardware devices such as computers, printers, and storage devices that are all in relative close proximity
repeater - device that amplifies and forwards signals
bridge - a smarter device that has knowledge about the nodes located on each seperate network
connects devices that are not in closer proximity
paclet - an info block w/ fixed size that is transmitted through the network as a single unit
long messages sent through WAN are separated into separate packages and are reassembled after all packets are collected
internet is made of a mix between LAN, WAN, and MAN networks
router - device that transmits message between two distinct networks
Internet Service Provider (ISP) - a business that provides access from a private network to the Internet or from a private network
protocol - mutually agreed-upon set of rules, conventions, and agreements for the efficient and orderly exchange of info
protocol hierarchy/protocol stack - 5 layers
physical, data link, network, transport, and application
goerns the exchange of binary digits across a physical communication channel such as a fiber optic cable, copper wire, or wireless radio channel
creates a 'bit pipe' between tow computers such that the bits entered in the pipe at one end can be read and understood by the computer located at the other end
detects errors (from interference, weather, or other factors) and corrects them
framing - identifying the start and end of a message
two sublayers
Medium Access Control protocals -determins how to arbitrate owbnership of a shared communication line when multiple nodes want to send messages at the same time
Logical Link Control protocols - solves the error detection and correction problem and ensures messages arrive at destination
Medium Access Control protocols - determines how to arbitrate the ownership of a shared communication channel when muyltiple nodes want to send messages at the same time
centralized - master control node is responsible for which node gets ownership of a line any moment
problem is that it would make the arbitration of the communication channel very slow as all nodes would have to repeatedly communicate with the master node
contention - based on nodes sending/transmitting info as soon as line becomes idle
problem is that as soon as the line becomes idle, multiple nodes may transmit their data resulting in repeated collisions
problem is solved as nodes nowadays transmit their data at irregular intervals, decreasing the chance of data collisions
ensures delivery of a message to is ultimate destination
IP/Internet Procotol
Domain Name System (DNS) - converts host names to IP Adresses
sends message to programs within a computer
port number - second level of address that identifies a specific machine on a network and a program munning on it
Transport Control Protocol (TCP)
transfers messages between two programs on different computers
protocols for implementing the end-user services provided by a network
interface between the IoT device and the network with which it will communicate
webpages are identified by "URL" or Uniform Resonance Locator
Hyptertext Transfer Protocol (HTTP) - acceses the hyptertext or procotl which the accessing computer what typ[e of info is on a web page
Schneider, G. Michael, and Judith L. Gersting. Invitation to Computer Science. Cengage Learning, 2019